A smart utility network (SUN) is a low rate (5 kb/s to 1 Mb/s), low power wireless communications technology that is specifically designed to be used in utility metering applications, such as transmitting electric, gas, or water usage data from the one or more meters on the customer premises to a data collection point operated for a utility.
In the prior known solutions, different physical layers (PHYs) can be used for communications in networks such as SUN including features such as frequency shift keying (FSK), direct sequence spread spectrum (DSSS), and orthogonal frequency division multiplexing (OFDM). In an example DSSS communications system that is a closed utility network, the devices that are allowed into the network can be controlled by the utility or the network operator. Note that while some of the examples discussed herein include operation of smart utility networks, the arrangements disclosed as aspects of the present application are not so limited and can be applied and used in conjunction with DSSS communications networks, generally.
A network can be set up in a mesh configuration where devices can communicate with neighbor devices rather than just communicating with a hub. The mesh configuration helps to increase coverage since communication can be achieved even if the link from one device directly to the hub is poor. However, this can increase the amount of traffic that passes through some devices since they have to include packet data from their neighbors as well as transmitting their own data. A mesh network can be particularly appropriate for an urban or suburban area with a high density of meters and non-line-of-sight conditions between meters, where communication links between some meters and a central hub is poor.
A star configuration can be used. In a star configuration network, a hub communicates directly with each meter. This configuration can be appropriate for rural environments when the density of meters is low so that there may not be a convenient neighbor to use as an intermediate hop as in a mesh arrangement. A mix between a star and mesh configuration can also be used in some deployments.
Since utility meters have a long life span such as 20 years, there may be many generations of meters deployed in a utility network. The earlier deployed meters can be termed as legacy equipment. In one known example, all the legacy devices in the utility network can communicate using a frequency shift keyed (FSK) modulation scheme, often at a fixed data rate such as 50 kb/s, 100 kb/s or 150 kb/s.
A relevant standard has been promulgated by the IEEE, referred to as IEEE standard number 802.15.4g, entitled “Low-Rate Wireless Personal Area Networks (LR-WPANs)” issued Apr. 27, 2012 by the IEEE Computer Society and sponsored by the LAN/MAN Standards Committee. This standard identifies physical layer (PHY) specifications for low data rate, wireless, smart metering utility networks (SUN). The LR-WPAN standard is intended to provide a globally used standard that facilitates very large scale process control applications such as a utility smart-grid network capable of supporting large, geographically diverse networks with minimal infrastructure and containing potentially millions of fixed endpoints. Note that the aspects of the present application are not limited to particular applications, including the SUN applications and/or LR-WPAN standard network applications, but the various arrangements that form aspects of the present application are applicable to such applications.
FIG. 1 is an illustration of a traditional SUN network. Depicted in FIG. 1 is a traditional SUN network 100 consisting of a single communication channel 110 and multiple transceiver nodes 120A, 120B, 120C, 120D . . . 120N. In this example prior known network arrangement, the individual nodes negotiate with the other nodes for free time on the single channel for communicating their information. A collision sense scheme is used to prevent interference, and the network can be referred to as a “collision sense multiple access” (CSMA) network.
FIG. 2 is a block diagram of a known prior approach transceiver 200 used in a SUN network. Transceiver 200 is depicted with antenna 210 coupled to a PA/LNA (power amplifier/low noise amplifier) 212 which is coupled to a radio frequency (Radio Front End) front end circuit and sampler 214. The radio front end circuit 214 is coupled to a processor 216 which is coupled to a power line circuit 218. Power line circuit 218 communicates with the power line 220. A SDR (software defined radio) is comprised of software running on a programmable device 216 such as a DSP, or a pair of DSPs, to implement a radio transceiver function. In 216, CPU1 which is numbered 230 can be, for example, a DSP with a low power coprocessor (coprocessor 1) 232 that communicates with the radio front end circuit 214. CPU2 240 is a DSP with a low power coprocessor (coprocessor 2) 242 that can communicate with the power line circuit 218. This arrangement forms the architecture for a single channel SDR within a tranciever node with CPU1 handling the wireless computations/communications, for a non-limiting example, and CPU2 handling the power line computations/communications. Specific commerically available components that can be used for forming a transceiver of this example architecture include a Texas Instruments Incorporated integrated circuit CC1260 that can be arranged to serve as the radio front end circuit 214, a Texas Instruments Incorporated analog front end integrated circuit AFE032 arranged to serve as the power line interface circuit 218 and a Texas Instruments Incorporated TMS320F28377D dual core microcontroller that can be arranged to serve as dual core processor 216. The microcontroller circuit contains a pair of Control Law Accelerators (CLA) that function as the coprocessors 232 and 242. While these example commercial parts are listed as illustrative implementation details, the transceiver can be implemented using other commercially available integrated circuits, or by designing custom or semi-custom integrated circuits for various parts of the transceiver, for example FPGA, CPLD, ASIC or full custom integrated circuits could be used. The transceiver can be formed using a module, circuit board, prototyping card, and the like. Discrete components can be used for some functions of the transceiver.
In the example prior known example transceiver of FIG. 2, two DSP processors CPU1 and CPU2 are used, however only a single channel modem is provided. The result is a limit on the bandwidth available for network communications. Improvements in communication systems are therefore needed in order to provide additional bandwidth and capacity for achieving additional system performance. In the SUN application, improvements are needed in providing additional network communication capacity without the need for additional hardware components and without a substantial increase in costs.